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Mining Methods and Slope Stability Evaluation for Expanded Development of the Walstrum Aggregate Quarry <br /> 3.1. Site Specific Survey of Structural Geological in the Walstrum Quarry <br /> In order to confirm the geological findings by Schowchow (1989) and to further evaluate the <br /> cohesiveness and interaction of joint structures and foliation planes, a site-specific survey was <br /> performed at various exposed rock faces in the quarry. The author and Stevan O'Brian of <br /> Environment, Incorporated conducted this survey on February 1 and 5, 2002. A summary of <br /> survey data and photos are included in Attachment 1. <br /> The findings of this survey verify the geological conditions described by Schowchow. The gneiss <br /> formations in the Walstrum pit, lying in the northeastern flank of the Idaho Springs Anticline, are <br /> indeed bounded to the south by the Floyd Hill Fault. In his report, Schowchow described the <br /> exact location and strike of this fault. At survey location 1, the measured strike of the Floyd Hill <br /> fault was N 45' W. Schowchow found it striking between N 30' W and N 55' W. <br /> Schowchow also found that the foliation of the predominant gneiss formations were striking East- <br /> West and dipping from 40 to 63 degrees toward the northeast and northwest. The average <br /> measured foliation dip was 48 degrees. The results of the site-specific survey confirmed this <br /> finding. At the measurement locations in the recent survey, the average strike of the gneiss <br /> foliation was N 127' E. <br /> REVEY Associates,Inc. Page 6 of 14 October,2001 <br />